1. Field of the Invention
The present invention relates to an endoscope system.
2. Description of the Related Art
Conventionally, an endoscope system including an endoscope configured to pick up an image of an object inside a subject, a video processor configured to generate an observation image of the object, the image of which is picked up by the endoscope, and a monitor configured to display the observation image generated by the video processor has been widely used in a medical field, an industrial field, and the like.
In such an endoscope system, in order to reduce noise of an endoscope image, a noise reduction processing function is provided inside the video processor. Since the noise of the endoscope image depends on a performance of an image pickup device loaded on the endoscope, strength of noise reduction needs to be adjusted according to a characteristic of the image pickup device.
For example, Japanese Patent Application Laid-Open Publication No. 2012-17735 discloses an endoscope system including a noise reduction circuit configured to change noise reduction strength according to a gain correction value multiplied with video signals. The noise reduction circuit performs processing of increasing the noise reduction strength in a case where the gain correction value is larger than 1, and lowering the noise reduction strength in the case where the gain correction value is smaller than 1.